1. Field of the Invention
The present invention relates to a device and method for application of a liquid or gel-like surgical material to a target site within a body cavity. The apparatus and methods of the present invention are suitable for use in laparoscopic and endoscopic surgical procedures, as well as open-incision type procedures.
2. Background
Surgical prosthetic materials are used with a wide variety of surgical procedures. For example, prosthetic materials often are associated with hernia repair. Hernias are abnormal protrusions of an organ or other body structure through a defect or natural opening in a covering membrane, muscle or bone. Hernia repair typically involves replacement of the protruding tissue and repair or reconfiguration of the opening from which it protruded.
Surgical prostheses used in hernia repair and other procedures may include mesh-or gauze-like materials, which support the repaired hernia or other body structures, and/or anti-adhesion barriers, which often are placed between organs or tissues having different structures. Anti-adhesion barriers are used to reduce the incidence and severity of adhesions, e.g., fibrous scar tissue caused by inflammation, which are byproducts of almost all surgical procedures. Such adhesions can cause a variety of highly undesirable post-surgical complications, including small-bowel obstructions, infertility, loss of range of motion and chronic pain. In the case of heart surgery, adhesions are particularly elevate the risk associated with such procedures.
Anti-adhesion barrier products may be in the form of sheets, films, liquids or gels, and are known to prevent the formation of adhesions between internal organs and/or the abdominal wall. Proper placement of such surgical prostheses is sometimes difficult, particularly where laparoscopic and endoscopic surgical procedures are utilized.
Laparoscopic and endoscopic surgical procedures offer significant advantages relative to conventional surgical procedures, and can often avoid the risks associated with such conventional procedures, e.g., bleeding, infection, and damage to organs, nerves and blood vessels.
In laparoscopic procedures, surgery is performed in the interior of the abdomen through narrow tubes inserted therein. Similarly, in endoscopic procedures, surgery is performed in any hollow cavity of the body through narrow endoscopic tubes inserted through small entrance wounds in the skin.
Since only small diameter incisions are required in laparoscopic and endoscopic procedures, trauma to the body (e.g., to the abdominal wall) is minimized, and the time required for healing and post-operative care is significantly shortened.
A number of devices have been developed for use in laparoscopic, endoscopic and open-incision delivery of surgical materials. Many of these devices are suitable for delivery of surgical material in the form of a sheet, film, mesh or gauze to a target site within a body cavity. (See, e.g., U.S. Pat No. 5,503,623, U.S. Pat. No. 5,350,387, and U.S. Pat. No. 5,304,187.)
Certain other laparoscopic and endoscopic devices were developed for delivery of liquid and gel-like medicinal materials. For example, U.S. Pat. No. 5,766,157 reports an instrument consisting of an elongated body adapted to receive a flexible delivery tube having a nozzle at its distal end. The nozzle of the delivery tube can be flexed to dispense a desired spray pattern into a patient""s abdominal cavity. However, due to its design and configuration, the device may only be used with low viscosity liquids. More specifically, the device is not capable of advancing a gel or liquid having a higher viscosity through the applicator tip to a target site. Indeed, the small diameter/dual conduit design of that device presents significant back-pressure even when applying a material having a moderate viscosity. Application is further limited in that the tip of the device is not adapted for spreading the medicinal material onto the target site in order to establish an even layer of the anti-adhesion product or other medicinal product. Further, the distal applicator tips are of a fixed size and thus present a limitation when inserted into a trocar. For example, the trocar must have a width greater than the applicator tip to permit the desired laparoscopic or endoscopic application.
There remains a need for improved devices for laparoscopic and endoscopic delivery of a wide variety of surgical materials, particularly liquid and gel-like surgical materials, to target sites within the body cavity. It would be highly desirable if such devices also were suitable for open-incision procedures as well. Further, it would be highly desirable to develop improved devices for laparoscopic, endoscopic and open incision procedures that would permit targeted delivery and even spreading of liquid and gel-like surgical materials including materials having relatively high viscosities. It would be particularly desirable for such devices to offer other mechanical advantages, e.g., reduced back-pressure during operation, as well as improved movement and flexibility within the body cavity for enhanced application of the surgical material.
Devices of the present invention are suitable for use in a variety of surgical procedures, including laparoscopic, endoscopic and open incision surgical procedures, for application of liquid and gel-like surgical materials to a target site within a body cavity.
Though devices of the present invention may be used for liquid and gel-like surgical materials having a broad range of viscosities, it is particularly well suited for application of relatively high viscosity materials. As used herein, xe2x80x9chigh viscosityxe2x80x9d refers to a viscosity between about 50,000 and about 90,000 centipoise (cp). Devices of the invention are suitable for delivery of numerous types of surgical materials, including anti-adhesion products such as SEPRAGEL (manufactured by Genzyme Corporation) and anatomical fillers such as tissue and organ sealants.
The novel design of the present invention offers surgical and medical personnel a number of advantages over devices of the prior art, including a simplified design, ease of use, flexibility in delivery, and more controlled and effective spreading of the surgical material at the target site. Indeed, the novel design of the present invention even permits dispensing of the surgical material against gravity.
Devices of the present invention generally comprise an elongated structural member (also referred to herein as a xe2x80x9crackxe2x80x9d) adapted for engagement with a conventional syringe; a cannula/hub assembly to which a highly flexible applicator tip is attached; a surface, e.g., a saddle portion, for holding the syringe that also permits conduit with the cannula/hub assembly and offers axial support to the cannula during the application procedure; and a drive/pawl mechanism which facilitates unloading of the surgical material from the cannula.
The cannula/hub assembly typically comprises a cannula having an elongated shaft which is connected, e.g., snap-fitted, to a hub portion; and preferably a joint which permits rotation of the shaft relative to the hub. The cannula/hub assembly is typically rotatably and removably connected to an interior portion of the device""s saddle, e.g., via a snap/pivot assembly. As will be appreciated by those skilled in the art, the cannula/hub assembly may be constructed of various materials, e.g., stainless steel, rigid epoxies, aluminum and the like.
As noted above, devices of the invention preferably comprise an applicator tip which is attached to the distal end of the cannula. Such a tip is preferably highly flexible, e.g., foldable, cylindrically adaptable and otherwise manipulatable, and permits application of the surgical material at variable delivery angles and against gravity. In particularly preferred embodiments of the invention, the applicator tip has a fan-shaped configuration. By way of illustration, the highly flexible fan-shaped applicator tip essentially allows the surgeon to apply the gel or liquid surgical material as one would apply paint to any given surface with a paint brush. In that way, targeted and controlled application of an even layer of surgical material is achieved.
The drive/pawl mechanism is preferably actuated by a handle or like feature that is easily accessible from a position external to the body cavity. In that way, the surgical material may be dispensed from the leading or distal end of the cannula without removing the apparatus from the body cavity.
Additionally, preferred embodiments of the invention further comprise a secondary mechanism (referred to herein as an xe2x80x9canti-backlash leverxe2x80x9d) which prevents syringe plunger expansion and permits air bolus priming.
Priming is typically performed before application of the surgical material to the target site, and preferably prior to introduction of the device into the trocar or secondary cannula (if the procedure is a laparoscopic or endoscopic one). Priming ensures that the surgical material, e.g., gel, is in a xe2x80x9cready to dispensexe2x80x9d mode and also ensures precision and accuracy with respect to the amount of gel to be delivered. Additionally, priming generally results in a small amount of the gel being applied to the applicator tip which acts as a lubricant and allows for easier transition of the device through the trocar or secondary cannula.
The anti-backlash lever also is critical during changeover of an empty or nearly empty (spent) syringe to a syringe containing an additional volume of surgical material. Upon actuation, the anti-backlash lever disengages the rack of the device so that the syringe may be removed and replaced without disrupting the on-going surgical procedure. Further, during such a changeover, air can become trapped in the cannula between one or more sections of the gel resulting in the presence of a compressible volume of air. Using devices of the present invention, that volume of air can easily be expensed and eliminated by re-priming of the device.
Though generally less preferred, as an alternative to the anti-backlash lever, another type of secondary mechanism may be employed for priming and preventing unwanted syringe plunger expansion. One example of such a mechanism preferably comprises a panel to which a manually operable spring-reinforced assembly is attached. In this embodiment, advancement of the surgical material and priming are achieved by actuation of one or more pivot levers which are in communication with the spring-reinforced assembly.
Using devices of the present invention, the surgical material is initially loaded into the syringe in a conventional manner; the syringe is connected to the cannula/hub assembly, e.g., by a luer taper fit connector, and seated in the saddle portion of the device. The device is preferably then primed by advancing the syringe plunger as needed, e.g., by applying forward pressure to the syringe plunger or using the handle to partially advance the drive/pawl mechanism. Once in proximity of the target site, the pawl/drive mechanism is actuated thereby advancing (unloading) the surgical material through the cannula at its distal end via the highly flexible fan-shaped applicator tip. In that way, devices of the invention permit flexible application of the surgical material to the target site with ease, accuracy and precision.
In addition to entry into the body cavity through an open incision, devices of the invention may be introduced through a conventional trocar during laparoscopic or endoscopic surgical procedures. For facile entry and movement within the trocar during such procedures, the applicator tip may be prolapsed or otherwise folded about the distal end of the cannula.
Methods for delivering a surgical material to a target site using devices of the present invention also are provided.
Methods of the invention generally comprise providing a device in accordance with the present invention, e.g., a device comprising a rack adapted for engagement with a conventional syringe, a cannula/hub assembly to which a suitable applicator tip is attached, a saddle for seating the syringe which permits conduit with the cannula/hub assembly, and a drive/pawl mechanism in communication with the rack for advancing the surgical material through the cannula/hub assembly; loading the surgical material into the syringe; connecting the syringe to the cannula/hub assembly, e.g., via a slip fit or self-locating type of engagement; seating the syringe in the saddle of the device; inserting the cannula portion of the device into the body cavity, e.g., directly or via a conventional trocar; positioning the applicator tip within proximity of the target site; applying the surgical material to the target site; and withdrawing the apparatus from the body cavity.
Preferred methods of the invention also may comprise priming the syringe and/or cannula. Priming may be achieved by forwardly advancing the syringe plunger or by actuation of the drive/pawl mechanism, e.g., using the handle of the device.
Methods of the invention also may further comprise replacing a spent syringe with a syringe containing an additional volume of surgical material during the application procedure. For example, certain procedures may require that a large volume of surgical material be applied to the target site. In such procedures, after the syringe has dispensed all or nearly all of its contents, it may be replaced with another syringe or with the same syringe which has been reloaded with additional surgical material. Using the anti-backlash lever (or the alternate secondary mechanism described above), the changeover of syringes can be achieved without removing the device from the body cavity or otherwise disrupting the procedure. Moreover, using devices of the invention, re-priming can be performed to eliminate air which might otherwise be introduced due to the changeover.
Preferred methods of the present invention also may comprise manipulating the leading or distal end of the cannula to facilitate application of the surgical material at variable delivery angles. Indeed, devices of the invention even permit dispensing of the surgical material against gravity. A highly flexible fan-shaped applicator tip is typically attached, e.g., via insert-molding or adhesive, to the distal end of the cannula to facilitate such manipulation during the application procedure.
The foregoing and other objects, features and advantages of the invention will become better understood with reference to the following description and appended claims.